Aren't all of these... descendants of Survivors
This is not the question whether the heirs are descendants of survivors from the death camps or not, they are entitled to this money it is theirs just as if your grandfather had owned a place in Italy or in Mexico and you inherited it.
If you need the money yourself why give it to the poor and needy?
In my opinion Datetree can inherit legally, sell his ancestors place, pay his succession taxes in Poland to the Notary , exchange it against US Dollars if he wishes and get in touch with the IRS in the US to check if he has anything extra to pay which I doubt.